Motors and Generators

Now that we have seen how electric currents produce magnetism, and magnetism produce electricity, we can make electric motors and generators.

Kinetic energy of a waterfall or other energy source can be turned into electricity by a generator. The electricity can be transported by a copper wire to a distant location. An electric motor can in turn be set moving.

Circuit diagram of generator and motor

In the above circuit diagram, we have a generator consisting of a spinning magnet. This induces an alternating current into the live wire by sending electrons moving one way when the north pole of the magnet sweeps past the wire, and sending electrons moving the opposite direction when the south pole sweeps past the wire.

As long as the switch to the electric motor is open, nothing much happens. The electrons in the wire are pushed back and forth a bit, but there is no load on the generator. Very little energy is consumed.

However, once the switch is closed, electricity starts flowing freely down past the magnet inside the motor. The strong magnetic field induced by the free flow of electrons set the magnet in the motor spinning.

The physical gaps between magnet and wire for both generator and motor are bridged by strong magnetic fields. The load on the motor is thus passed on to the generator.